NASA flies Boeing 747 with big telescope door open, oh Sofia

A German-built telescope is exposed during a flight of NASA’s Stratospheric Observatory for Infrared Astronomy 747SP on Dec. 18, 2009. Credit: Carla Thomas/NASA

On Dec. 18, NASA for the first time opened the doors of its Stratospheric Observatory for Infrared Astronomy in flight.

The observatory, known by its acronym, SOFIA, is a modified Boeing 747 equipped with a 98-inch German-built infrared telescope and doors that open to expose the telescope in flight. The Dec. 18 flight included two minutes with the telescope doors fully opened to allow engineers to understand how air flows in and around the telescope.